Microgravity is the name that has been adopted for very high-resolution gravity mapping. Microgravity surveys are typically used to detect sub-surface cavities or changes in sub-surface density. The Applied & Environmental Geophysics Research Group provides state-of-the-art microgravity services and presents this website as a useful source of reference for potential users.
This site introduces basic concepts of gravity, from Newton to Bouguer, and allows the user to perform a selection of surveys and to calculate the gravity anomaly over a void.
The applications section shows that microgravity technology is not restricted to cavity detection. A series of recent case studies are also provided to illustrate the power of the technique. More specific advice is always available by contacting us.
Microgravity is a geophysical method that measures minute changes in the force of the earth’s gravity. With modern equipment and careful field procedures, it is now possible to measure gravity changes as small as 1 part in 1,000,000,000. Changes in gravity measured at the earth's surface reflect the underlying geological structure, hence the accurate determination of gravity leads to an understanding of the ground beneath. It has been established that microgravity is an accurate and reliable method for detecting underground cavities, both natural and manmade. The application of this technique however is not restricted to void detection. High-resolution gravity has been used to monitor fluid flow in oil and geothermal reservoirs and to monitor aquifer recharge and depletion. Traditional gravity surveying as used in the oil and minerals industries has been given greater resolution by the use of microgravity acquisition and processing methods.
Did you know that a person on a moving train will be heavier when the train is moving east and lighter when the train is moving west? This is because the centrifugal force of the rotating earth opposes gravity. Objects moving eastward have a greater centrifugal force and therefore an apparently lower gravity.